Tail-shaft bearing assembly

ABSTRACT

In a propeller shaft bearing arrangement having a split bearing extending through an opening in the stern frame of a ship, one part of the bearing being removable while the ship is afloat and a seal being provided for preventing the entry of water through the opening, there is provided the improvement that the other part of the bearing may be adjusted in position or removed while the ship is afloat. An inflatable seal is provided for preventing the entry of water during the removal of the other part of the bearing. Jacks, rollers and a drive mechanism are provided for facilitating the removal of the other part, and taper wedges for securing the other part in its normal position.

[ Feb. 27, 1973 1 TAIL-SHAFT BEARING ASSEMBLY [75] Inventor: JohnArmstrong Clay,

- Cheshire, England [73] Assignee: Turnbull Marine Design CompanyLimited, Cheshire, England 221 Filed: June 1, 1970 21 Appl.No.:42,049

Sale,

[30] Foreign Application Priority Data [56] References Cited UNITEDSTATES PATENTS 1,831,857 11/1971 Goodnow ..308/3l 3,540,405

3 2/1966 Satterthwaite ..308/15 8/1967 Smith et a1. ..277/34.3

3,433,540 3/1969 Schneider ..308/36.l 3,470,842 10/1969 Clay ..1 15/34Primary ExaminerMilton Kaufman Assistant Examiner-Barry GrossmanAtt0meyBrady, OBoyle and Gates [57] ABSTRACT In a propeller shaftbearing arrangement having a split bearing extending through an openingin the stern frame of a ship, one part of the bearing being removablewhile the ship is afloat and a seal being provided for preventing theentry of water through the opening, there is provided the improvementthat the other part of the bearing may be adjusted in position orremoved while the ship is afloat. An inflatable seal is provided forpreventing the entry of water during the removal of the other part ofthe bearing. Jacks, rollers and a drive mechanism are provided forfacilitating the removal of the other part, and taper wedges forsecuring the other part in its normal position.

13 Claims, 5 Drawing Figures PATENTEUFEBZTISH sum 10F 2 R NMM INVENTDRJOHN ARMSTRONG CLAY M/Qd bfl;

ATTORNEYS PATENTEI] FEBZ 7 I973 SHEET 2 or 5' TAIL-SHAFT BEARINGASSEMBLY The present invention relates to propeller shaft bear in garrangements comprising a split bearing mounted in the stern frame of aship and supporting a propeller shaft extending through an opening inthe stern frame,

the bearing comprising a first bearing part which is removable from theshaft without disturbance of the shaft to allow inspection of the shaftwhile the ship is afloat, and a further bearing part which supports theshaft during the removal of the first bearing part.

It has previously been proposed to form the further bearing part in onepiece with the stern frame or as a part of a housing containing thebearing and inserted into the opening from aft of the stern frame. Thesepreviously proposed bearing arrangements have the disadvantage that itis not possible to adjust or remove the whole of the bearing, e.g., forservicing or replacement, while the ship is afloat.

According to the present invention, the further hearing part is alsoremovable inwardly of the ship, and a sealing arrangement is providedwhich prevents the entry of water between the shaft and the stern frameon removal of the further bearing part. Preferably, the furtherbearingpart is adjustable in position in the stern frame while the shipis afloat, e.g., while the ship is at loaded draught.

The sealing arrangement may comprise a radially or axially expansibleinflatable seal or both and may be provided between the hub of thepropeler and the stern frame.

Preferably, a mechanical seal at least part of which preferably extendsaround the aftermost end of the split bearing is provided which normallyprevents the entry of water through the opening and which is notdisturbed by removal of the first bearing part.

The mechanical seal may be provided between a propeller flange on theshaft and the bearing. The further part of the bearing may be the lowerhalf of the bearing and have a sealing portion extending around theupper bearing half and between a part of the mechanical seal and asealing face on the stern frame- This sealing portion may be in onepiece with the lower bearing half or may be a separate member secured tothe lower bearing half, and may be sealed to a radial sealing portion onthe upper bearing half. The mechanical seal may be provided between thelower bearing half and the sealing portion thereon.

The stern frame may be provided with a cradle for supporting thepropeller and the shaft on removal of the further bearing part.

The stem frame may have a portion arranged to serve as a lifting jacksupport during removal of the lower bearing part and lifting jacks,which may be hydraulic, may be provided preferably removably, betweenthe support and the lower bearing part.

A track may be provided beneath the lower bearing part along whichrollers supporting the lower bearing part run during withdrawal andreturn of the lower bearing part. The rollers may form parts ofcarriages insertable between the track and the lower bearing part.

The bearing may be normally supported on chocks which are removable tofacilitate the removal of the lower bearing part.

A drive mechanism may be provided for moving the lower bearing part toand from its normal position in the stern frame. A verticallydisplaceable support, e.g.,

a table on a scissor mechanism, may be provided forward of the sternframe to facilitate movement of the lower bearing part to and from theshaft.

Adjustable lateral stabilizing means, e.g., jacks, may be providedbetween the sides of the lower bearing part and the stern frame.

Hydraulic lifting means, which may be mounted for travel along an uppertrack, may be provided to facilitate the removal of the upper bearingpart.

Taper wedges may be provided at opposite sides of the further bearingpart for locating the latter in its normal operational position.

The invention will be more readily understood from the followingdescription of an embodiment thereof given by way of example withreference to the accompanying drawing, in which:

FIG. I shows a view taken in longitudinal section through a propellershaft bearing arrangement;

FIG. 2 shows a view taken along the line II--II of FIG. 1;

FIG. 3 shows a view taken along the line III-III of FIG. 1;

FIG. 4 shows on a larger scale a part of the view partial longitudinalsection taken along the line IV--IV of FIG. 2; and

FIG. 5 shows a view taken in section along the line V-V of FIG. 3;

As shown in the drawings, a propeller shaft 10 has a flange 11 to whicha propeller 12 is secured by propeller mounting bolts 13, and extendsinto an opening in the stern frame 15 of a ship.

The shaft 10 is supported in a split bearing of which the lower half isformed by a housing part 16 with a lining 17, and the upper half by abearing cap 18 with a lining 19.

The housing part 16 is formed at each side with a shoulder 20 whichshoulders 20 are supported by means of checks 21 (FIG. 2) on shoulders22 formed on the stern frame 15, and hydraulic jacks 24 are providedbetween the stern frame 15 and the bearing cap 18 for securing thebearing in position.

The bearing cap 18 can be removed to allow inspection of the shaft byreleasing and removing the hydraulic jack 24 and then lifting thebearing cap 18 by retracting hydraulic lifting jacks 26. The liftingjacks 26 can run on rollers along an upper track 27 to carry the bearingcap 18 forwardly from the stern frame 15.

The forward end of the split bearing is sealed to the shaft by amechanical seal 28, which has of course to be removed before the bearingcap can be removed.

A semi-annular radial sealing portion 30 bolted to the housing partextends upwardly therefrom around the rear end of the bearing cap 18,and a mechanical seal 31 seals the flange 11 to the lower half ofthehousing part 16 and to the radial sealing portion 30, which are in turnsealed to a radial sealing face 32 on the stern frame 15 by a sealingring 33. The mechanical seal 31, the radial sealing portion 30 and thesealing ring 33 form parts of a sealing arrangement which prevents theentry of sea water while the bearing is in use and also when the bearingcap 18 is removed as described above to allow inspection of the shaft,which can be done without disturbing this sealing arrangement or theshaft.

While in the present embodiment the radial sealing portion 30 is securedby bolts 34 (FIG. to the housing part 16, it may be formed in one piecetherewith.

The bearing cap 18 is formed with a further radial sealing portion 35which is sealed by a resilient seal member 36 to the radial sealingportion 30.

Beneath the housing part 16, there is a space between the housing part16 and the stern frame into which hydraulic jacks 37 can be inserted ona slipper 38. By expanding the hydraulic jacks 37, the housing part 16can be lifted from the chocks 21, which can then be removed from betweenthe housing part 16 and the shoulders 22. On subsequent retraction ofthe hydraulic jacks 37, the housing part 16 is lowered until thepropeller 12 comes to rest in a cradle 40 made of Tufnol (RegisteredTrade Mark) or like material. The housing part 16 comes to rest onroller carriages 41 which can run along lower tracks 42 to carry thehousing part 16, together with its lining 17, forwardly from the normalposition in which it is shown in FIG. 1. The forward movement of thehousing part 16 and lining 17 may be effected by means of a withdrawaland return gear indicated generally by reference numeral 44, which maycomprise a motor driven endless chain 45 connected by an arm 46 to thehousing part 17.

When the housing part 16 has thus been withdrawn forwardly, the housingpart 16, its lining 17, and the mechanical seal 31 can be examined,serviced or, if required, replaced, and the propeller mounting bolts 13can be examined and, if necessary, tightened from within the ship andwhile the ship is afloat.

To prevent the entry of sea water while this is done, inflatable seals50 and 51 are inflated. The inflatable seal 50 is provided in a ropeguard 52 formed on the stern frame 50 and when inflated presses radiallyinwardly, against the periphery of the hub of the propeller 12. Theinflatable seal 51 is also provided in the rope guard 52 when inflatedpresses axially against the forward end of the propeller hub. Theinflatable seals 50 and 51 are resilient and maintain sealing contactwith the propeller hub throughout the small movement of the latter whichoccurs during the above described withdrawal of the housing part 16.

When the housing part 16 has been moved forwardly as described above, itcan be supported on a table (not shown) which is in turn supported on ascissors mechanism (not shown) by means of which the table can belowered and raised to facilitate inspection and, if required,replacement of the housing part 16 or its lining 17. l

The return of the housing part 16 to its normal position is the reverseof the above described withdrawal.

A wedge member 53 at each side of the bearing is engaged in verticalkeyways 54 and 55 formed in the stern frame 15 and the housing part 16.A bolt 56 in threaded engagement with each wedge member 53 is rotatablysecured to the housing part 16. The wedge members 53 are urgeddownwardly by rotation of the bolts 56 to effect lateral axial locationof the housing part 16 relative to the stern frame 15. By this means,the position of the housing part 16 relative to the stern frame can beadjusted verticallyand horizontally, i.e., foreand-aft and athwartship.

With the above described bearing arrangement the bearing cap 18 and itslining 19 can be readily removed and if required replaced while the shipis afloat and without disturbing the shaft 10 and the mechanical seal 31to allow inspection of the shaft 10 as far as the flange 11, the inboardside of the mechanical seal 31 and the upper bearing half.

By also removing the lower bearing half and the mechanical seal 31 asdescribed above, these can be examined and if necessary replaced withoutuncoupling the shaft 10 or propeller 12 while the ship is afloat andwithout drydocking the ship.

The forward mechanical seal 28 can also of course be replaced while theship is afloat.

By reversing the propeller mounting bolts 13, these bolts can also bereplaced while the ship is afloat, and if necessary the propeller 12 canbe replaced without drydocking the ship.

The after mechanical seal 31 is radially outwardly spaced from the shaft10, thus allowing the splitbearing to extend rearwardly for supportingthe shaft as far rearwardly as the propeller flange 11. In amodification of the illustrated embodiment, the split bearing mayproject rearwardly beyond the mechanical seal 31.

While in the present embodiment two support shoulders 22 are provided,it is possible to vary the number or position of support surfacesprovided on the stern frame for supporting the housing part 16, and touse these surfaces to support the housing part 16, or act inco-operation with other surfaces, during withdrawal of the housing part16. By altering the shape of the chocks 21 the alignment and position ofthe housing part 16 in the stern frame 15 can be adjusted.

The hydraulic lifting jacks 26 may be replaced by mechanical jacks, andthe withdrawal and return gear 44 may be modified, e.g., by using otherhydraulic, electrical or mechanical means and/or by locating this gearcloser to the axis of the shaft.

Axial location of the bearing cap 18 is ensured by tapered keys, ofwhich one is indicated at 61, set into the housing part 16, which causecompression of the sealing member 36.

Iclaim:

1. A propeller shaft bearing arrangement comprising a split bearingmounted in the stern frame of a ship and supporting a propeller shaftextending through an opening in the stern frame, the split bearinghaving an upper bearing part and a lower bearing part, means operativelyconnected to the upper bearing part for lifting the upper bearing partaway from its normal operating position over the shaft and for moving itlongitudinally inward of the ship, means operatively connected to thelower bearing part for lowering said lower bearing part away from itsnormal operating position below the shaft and for moving said lowerbearing part longitudinally inward of the ship, means mounted betweensaid frame and said lower bearing part for radially adjustable securingsaid lower bearing part in said opening, and seal means between theshaft and the stern frame operable to prevent the entry of water betweenthe shaft and the stern frame on removal of said bearing parts.

2. A propeller shaft lower bearing part arrangement as claimed in claim1, wherein the means for radially adjustable securing said bearing insaid opening includes taper wedges at opposite sides of said lowerbearing part for adjustable locating the latter in its normaloperational position.

3. A propeller shaft bearing arrangement as claimed in claim 1, whereinthe sealing means comprises an inflatable seal.

4. A propeller shaft bearing arrangement as claimed in claim 3, whereinthe seal means is radially expansible by inflation to seal said opening.

5. A propeller shaft bearing arrangement as claimed in claim 3, whereinthe seal means is axially expansible by inflation to seal the opening.

6. A propeller shaft bearing arrangement as claimed in claim 3, whereinthe seals means is provided between the stern frame and the hub of apropeller on the shaft.

7. A propeller shaft bearing arrangement as claimed in claim 1, whereinsaid lower part of the bearing is provided with a seal sealing the splitbearing to the stern frame.

8. A propeller shaft bearing arrangement as claimed in claim 8, whereinthe seal comprises a sealing portion secured to said lower bearing partat opposite sides of the shaft and extending around said upper bearingpart.

9. A propeller shaft bearing arrangement as claimed in claim 1, whereinrollers are provided for supporting said lower bearing part duringmovement of the latter to and from its normal operational position.

10. A propeller shaft bearing arrangement as claimed in claim 9, whereinthe rollers form parts of carriages disposed between said lower bearingpart and a track provided on the stern frame.

11. A propeller shaft bearing arrangement as claimed in claim 9, whereinhydraulic jacks are provided for lifting said lower bearing part toallow installation of the rollers beneath said lower bearing part.

12. A propeller shaft bearing arrangement as claimed in claim 1, whereina drive mechanism is provided for moving said lower bearing part to andfrom its normal position.

13. A propeller shaft bearing arrangement as claimed in claim 1, whereinhydraulic lifting means mounted for travel along a path above the shaftare provided for lifting said upper bearing part.

1. A propeller shaft bearing arrangement comprising a split bearingmounted in the stern frame of a ship and supporting a propeller shaftextending through an opening in the stern frame, the split bearinghaving an upper bearing part and a lower bearing part, means operativelyconnected to the upper bearing part for lifting the upper bearing partaway from its normal operating position over the shaft and for moving itlongitudinally inward of the ship, means operatively connected to thelower bearing part for lowering said lower bearing part away from itsnormal operating position below the shaft and for moving said lowerbearing part longitudinally inward of the ship, means mounted betweensaid frame and said lower bearing part for radially adjustable securingsaid lower bearing part in said opening, and seal means between theshaft and the stern frame operable to prevent the entry of water betweenthe shaft and the stern frame on removal of said bearing parts.
 2. Apropeller shaft lower bearing part arrangement as claimed in claim 1,wherein the means for radially adjustable securing said bearing in saidopening includes taper wedges at opposite sides of said lower bearingpart for adjustable locating the latter in its normal operationalposition.
 3. A propeller shaft bearing arrangement as claimed in claim1, wherein the sealing means comprises an inflatable seal.
 4. Apropeller shaft bearing arrangement as claimed in claim 3, wherein theseal means is radially expansible by inflation to seal said opening. 5.A propeller shaft bearing arrangement as claimed in claim 3, wherein theseal means is axially expansible by inflation to seal the opening.
 6. Apropeller shaft bearing arrangement as claimed in claim 3, wherein theseals means is provided between the stern frame and the hub of apropeller on the shaft.
 7. A propeller shaft bearing arrangement asclaimed in claim 1, wherein said lower part of the bearing is providedwith a seal sealing the split bearing to the stern frame.
 8. A propellershaft bearing arrangement as claimed in claim 8, wherein the sealcomprises a sealing portion secured to said lower bearing part atopposite sides of the shaft and extending around said upper bearingpart.
 9. A propeller shaft bearing arrangement as claimed in claim 1,wherein rollers are provided for supporting said lower bearing partduring movement of the latter to and from its normal operationalposition.
 10. A propeller shaft bearing arrangement as claimed in claim9, wherein the rollers form parts of carriages disposed between saidlower bearing part and a track provided on the stern frame.
 11. Apropeller shaft bearing arrangement as claimed in claim 9, whereinhydraulic jacks are provided for lifting said lower bearing part toallow installation of the rollers beneath said lowEr bearing part.
 12. Apropeller shaft bearing arrangement as claimed in claim 1, wherein adrive mechanism is provided for moving said lower bearing part to andfrom its normal position.
 13. A propeller shaft bearing arrangement asclaimed in claim 1, wherein hydraulic lifting means mounted for travelalong a path above the shaft are provided for lifting said upper bearingpart.